1. Performance timeline which shows major events (e.g. DOMContentLoaded, load event) and the network / scripts which blocked them
2. Initiators for reflow, layout, etc. events. Currently it's really easy to identify a JavaScript hotspot if it's pure JS but it's hard to learn what's triggering hundreds of reflows, particularly in non-obvious cases such as CSS transitions.
1. Performance timeline which shows major events (e.g. DOMContentLoaded, load event) and the network / scripts which blocked them
2. Initiators for reflow, layout, etc. events. Currently it's really easy to identify a JavaScript hotspot if it's pure JS but it's hard to learn what's triggering hundreds of reflows, particularly in non-obvious cases such as CSS transitions.